This proposal requests support to continue a successful predoctoral and postdoctoral training program designed to provide training in molecular and cellular aspects of drug abuse research. The University of Washington School of Medicine has strong research programs studying molecular aspects of drug receptor signaling mechanisms in several departments, and this training program has dramatically facilitated the coordination of training and collaboration of research effort among the drug abuse researchers at this institution. We expect that the continued application of increasingly sophisticated biochemical and physiological methods will provide important advances in our understanding of the mechanisms by which specific drugs of abuse act. It is the intent of this program to identify and support four predoctoral students and three postdoctoral fellows interested in studying molecular and cellular mechanisms of drug action of specific abused drugs. Beyond the directly beneficial effects on the careers of the trainees, one of the most significant successes of the previously funded program has been its catalytic effect on the research environment at this institution. A funded Drug Abuse Research Training Program will continue to serve as an important catalyst to focus research effort at this institution on the basic neurobiology of a significant health issue.